Improvements in and relating to tamper evident seals

ABSTRACT

A tamper evident seal for a container includes a screw thread and a closure adapted for use with the container. The seal comprises a normally circular ring which is frangibly linked to the closure. The ring has one or more inwardly extending protrusions, and the container has one or more corresponding outwardly extending protrusions adjacent its screw thread. Faces of the protrusions are configured such that the leading face of each ring protrusion approaches the forward face of each container protrusion when the closure is fitted onto the container. Protrusions are situated in spaced apart locations about a perimeter of the container or ring and the normally circular ring is able to pass over the protrusion or protrusions on the container substantially without stretching by deforming out of round. The closure is adapted for use as a drinking vessel and the container is substantially bottle shaped.

FIELD OF THE INVENTION

This invention relates to tamper evident seals for use with screw top containers, and in particular, but not exclusively to tamper evident seals for use with a combined drinking vessel and cap for a drinks container.

BACKGROUND

The applicant of the present invention is also the applicant of the New Zealand patent application numbers 527195, 538172 and 551470, and has been involved in the development of packaging systems for single serve drinks for a number of years. The present invention relates to an improved tamper evident seal for use with the packaging systems described in the above patent applications and addresses problems that have been experienced during the development process.

The problem has been to devise a tamper evident seal for use with a drink packaging product which includes both a bottle and a drinking vessel. Early attempts to solve this problem have involved the use of a paper or plastic wrap fitted over the join between the mouth of the drinking vessel and the body of the bottle.

However this type of seal has a number of problems. It involves the use of an additional item of material, and this additional item must be fitted by adding another step to the production line used to fill and seal the drink packages. This additional material and production step adds to the cost of producing each packaged drink.

Also, a tamper evident seal which is removed from the packaged drink when the package is opened is a problem. The person opening the drink has one hand to hold the bottle and one to hold the drinking vessel, and another item can be inconvenient and is likely to become a litter hazard. This problem can be significant in an airline situation for example, where seated passengers are provided with drinks, and where a tear off seal is yet another object to handle and one that will often end up on the floor or under seat cushions etc.

In New Zealand patent application number 538172 a tamper evident seal was developed which was situated within the drinking vessel and which engaged with the neck of the bottle. At present it is considered that the method of manufacture could be improved upon to reduce manufacturing costs, and or to improve the overall feel and appearance of the drinking vessel.

The previous designs have incorporated tamper evident seals of the type that are ideally formed from a plastics material having a useful degree of elasticity and memory. Plastics materials having these characteristics, and relatively low cost, are polypropylene and polyethylene. For this reason, a combined drinking vessel and cap that incorporates a tamper evident seal has had to be manufactured in at least two parts, or be manufactured entirely from polypropylene or polyethylene.

However, polypropylene or polyethylene are not the ideal choice for a drinking vessel when trying to manufacture a drinking vessel that is as “glass” like as possible. In such a case it is preferable to use a styrene plastics material which can be clear and a little more “glass” like in appearance and feel.

What is needed is a tamper evident seal design which does not require the use of a plastics material having a similar degree of elasticity and memory as that found in polypropylene or polyethylene materials. A tamper evident seal design that could be manufactured from a more rigid plastics material, for example a styrene plastics material, would facilitate the manufacture of a combined drinking vessel and cap from this material. This would allow the desirable characteristics of this material to be taken advantage of, while allowing greater opportunity to keep manufacturing costs low.

The use of a single plastics type for both the body of the drinking vessel and for the cap/base portion would also allow the use of ultrasonic welding if the drinking vessel is manufactured in two or more parts. The use of ultrasonic welding is desirable since it can improve the leak resistance of an assembled drinking vessel.

In this specification unless the contrary is expressly stated, where a document, act or item of knowledge is referred to or discussed, this reference or discussion is not an admission that the document, act or item of knowledge or any combination thereof was at the priority date, publicly available, known to the public, part of common general knowledge; or known to be relevant to an attempt to solve any problem with which this specification is concerned.

OBJECT

It is therefore an object of the present invention to provide a tamper evident seal design which will at least go some way towards overcoming the above mentioned problems, or at least provide the public with a useful choice.

STATEMENTS OF THE INVENTION

Accordingly, in a first aspect, the invention consists in a tamper evident seal for a container having a screw thread and a closure means adapted for use with the container, the tamper evident seal comprising a normally circular ring which is frangibly linked to the closure means, the ring having one or more inwardly extending protrusions, and the container having one or more corresponding outwardly extending protrusions adjacent its screw thread, the or each protrusion on the ring having a leading face, and an opposing trailing face, and the or each protrusion on the container having a forward face and an opposing aft face, the faces being configured such that the leading face of the or each ring protrusion approaches the forward face of the or each container protrusion when the closure means is being fitted onto the container, and wherein any protrusions on the container are situated or grouped in spaced apart locations about a perimeter of the container and the normally circular ring is able to pass over the protrusion or protrusions on the container substantially without stretching and by deforming out of round.

Preferably the or each trailing face is substantially aligned at an acute angle to a tangent of an inner surface of the ring at the point where the trailing face meets the inner surface of the ring.

Preferably the or each aft face is substantially aligned at an acute angle to a tangent of the perimeter of the container at the point where the aft face meets the perimeter of the container.

Optionally there are two or more protrusions spaced about the perimeter of the container.

Preferably where there are two protrusions on the container they are located on opposite sides of the container, and where there are more than two protrusions they are grouped into two groups with each group being on opposite sides of the container.

Preferably each of the protrusions in any group of protrusions on the container are linked by a web extending between adjacent protrusions.

Preferably the or each web is narrower than the protrusions which it links.

Preferably the or each web substantially connects the faces of adjacent protrusions that face the screw threads of the container.

Preferably a face of the or each protrusion on the container facing the screw threads of the container is bevelled with respect to the outer surface of the container.

Preferably a face of the or each web facing the screw threads of the container is bevelled with respect to the outer surface of the container.

Preferably the or each forward face is bevelled with respect to the outer surface of the container.

Preferably the or each leading face is bevelled with respect to an inner surface of the ring.

Preferably the frangible link includes a line of weakness between the ring and the closure means.

Preferably the ring protrusions can be bevelled on their upper and/or lower faces.

In a second aspect, the invention consists in a tamper evident seal for a container having a screw thread and a closure means adapted for use with the container, the tamper evident seal comprising a normally circular ring which is frangibly linked to the closure means, the ring having one or more inwardly extending protrusions, and the container having one or more corresponding outwardly extending protrusions adjacent its screw thread, the or each protrusion on the ring having a leading face, and an opposing trailing face, and the or each protrusion on the container having a forward face and an opposing aft face, the faces being configured such that the leading face of the or each ring protrusion approaches the forward face of the or each container protrusion when the closure means is being fitted onto the container, and wherein any protrusions on the ring are situated or grouped in spaced apart locations about an inner surface of the ring and the normally circular ring is able to pass over the protrusion or protrusions on the container substantially without stretching and by deforming out of round.

Preferably the or each trailing face is substantially aligned at an acute angle to a tangent of the inner surface of the ring at the point where the trailing face meets the inner surface of the ring.

Preferably the or each aft face is substantially aligned at an acute angle to a tangent of a perimeter of the container at the point where the aft face meets the perimeter of the container.

Optionally there are two or more protrusions spaced about the inner surface of the ring.

Preferably where there are two protrusions on the ring they are located on opposite sides of the ring, and where there are more than two protrusions they are grouped into two groups with each group being on opposite sides of the ring.

Preferably each of the protrusions in any group of protrusions on the ring are linked by a web extending between adjacent protrusions.

Preferably the or each web is narrower than the protrusions which it links.

Preferably the or each web substantially connects the faces of adjacent protrusions that face away from the screw threads of the closure means.

Preferably a face of the or each protrusion on the container facing the screw threads of the container is bevelled with respect to an outer surface of the container.

Preferably a face of the or each web facing away from the screw threads of the closure means is bevelled with respect to the inner surface of the ring.

Preferably the or each forward face is bevelled with respect to the outer surface of the container.

Preferably the or each leading face is bevelled with respect to the inner surface of the ring.

Preferably the frangible link includes a line of weakness between the ring and the closure means.

Preferably the ring protrusions can be bevelled on their upper and/or lower faces.

In a third aspect, the invention consists in a liquids packaging product incorporating at least one tamper evident seal substantially as specified herein.

Preferably the closure means is also adapted for use as a drinking vessel.

Preferably the container is substantially bottle shaped.

Preferably the closure means or drinking vessel is manufactured entirely, or primarily, from a styrene plastics material.

To those skilled in the art to which the invention relates, many changes in construction and widely differing embodiments and application of the invention will suggest themselves without departing from the scope of the invention as defined in the appended claims. The disclosures and the descriptions herein are purely illustrative and are not intended to be limiting.

DESCRIPTION

Further aspects of the present invention will become apparent from the following description which is given by way of example only and with reference to the accompanying drawings in which:

FIG. 1 is a perspective view of a bottle adapted for use with a tamper evident seal of the present design,

FIG. 2 is a side elevation view of the bottle,

FIG. 3 is a side elevation view of a base of a drinking vessel incorporating the tamper evident seal of the present design,

FIG. 4 is a cross sectional view of the bottle shown assembled with a drinking vessel incorporating the base,

FIG. 5 is a perspective view of a main body of the drinking vessel,

FIG. 6 is a perspective view of the base of the drinking vessel,

FIG. 7 is a cross sectional view AA referenced in FIG. 2, and

FIG. 8 is a cross sectional view BB referenced in FIG. 3.

FIG. 9 is cross sectional view of a main body of the bottle shown assembled with a drinking vessel incorporating the base,

FIG. 10 is a cross sectional view of the base of the drinking vessel,

FIG. 11 is a close up cross sectional view BB referenced in FIG. 9,

FIG. 12 is a close up cross sectional view CC referenced in FIG. 9.

FIG. 13 is an outer perspective view of the base of the drinking vessel,

FIG. 14 is an inner perspective view of the base of the drinking vessel,

FIG. 15 is a cross sectional view of the base of FIG. 14,

FIG. 16 is a top plan cross sectional view of the base of FIG. 14.

FIG. 17 is a cross sectional view AA of a main body of the drinking vessel as referenced in FIG. 16,

FIG. 18 is a top plan sectional view CC of the ring of the base as referenced in FIG. 15,

FIG. 19 is a perspective view of the bottle without the drinking vessel,

FIG. 20 is a cross sectional top plan view of the bottle of FIG. 19.

FIG. 21 is a cross sectional side view perspective view of the bottle,

FIG. 22 is a cross sectional end view of the base of the bottle, and

FIG. 23 is a perspective view of the drinking vessel showing the groove.

With reference to FIGS. 1 to 8, a tamper evident seal (10) of the present invention is shown. The seal (10) is designed for use with a container (11) having a screw thread (13) and a closure means (15) that is adapted for use with the container (11). The tamper evident seal (10) comprises a normally circular ring (17) which is connected to the closure means (15) by a frangible link (19). The closure means (15) forms a cap which can seal off an opening (20) of the container (11) and is provided with an internal screw thread (21) which is adapted to mate with the external screw thread (13) of the container (11).

In this example the frangible link (19) is shown as a number of narrow links (22) which bridge between the closure means (15) and the ring (17) providing a line of weakness which can easily be broken to allow the closure means (15) to be removed from the container (11) while leaving the ring (17) behind and retained about a neck (23) of the container (11).

The ring (17) has a number of inwardly extending protrusions (25), and the container (11) has a number of corresponding outwardly extending protrusions (27) adjacent its screw thread (13). Each protrusion (25) on the ring (17) has a leading face (29), and an opposing trailing face (31), and each protrusion (27) on the container (11) has a forward face (33) and an opposing aft face (35). The faces are configured such that the leading face (29) of each ring protrusion (25) approaches the forward face (33) of each container protrusion (27) when the closure means (15) is being fitted onto the container (11).

When the closure means (15) is screwed onto or off the container (11) the ring protrusions (25) interfere with the container protrusions (27) since the inner most diameter of the tips of the ring protrusions (25) is less than the outer diameter of the tips of the container protrusions (27).

To aid the passage of the ring protrusions (25) past the container protrusions (27), while the closure means (15) is being screwed onto the container (11), each forward face (33) can be bevelled with respect to the outer surface of the neck (23) of the container (11). Similarly, each leading face (29) can be bevelled with respect to an inner surface (34) of the ring (17).

In this example there are eight ring protrusions (25) equally spaced about the inner surface (34) of the ring (17), and there are four container protrusions (27) situated on the neck (23) of the container (11). It can be seen that the protrusions (27) on the container (11) are situated or grouped in spaced apart locations about a perimeter of the neck (23) of the container (11). And since the protrusions are grouped, in pairs in this example, a significant portion, or at least half of the perimeter of the neck (23) has no protrusions. The ring protrusions (25) can easily pass over the parts of the perimeter of the neck (23) that have no protrusions. And, the ring protrusions (25) can pass over the parts of the neck (23) that have protrusions by the ring (17) deforming slightly out of round, that is, by becoming slightly oval or elliptical.

This means that the normally circular ring (17) can pass over the protrusions (27) on the container (11), as the closure means (15) is screwed onto the container (11), substantially without having to stretch, but rather by simply deforming out of round. As will be explained further below, the container protrusions (27) are designed to facilitate this passage of the ring protrusions (25) as the closure means (15) is screwed onto the container (11), but to resist the passage when the closure means (15) is unscrewed from the container (11).

It can be seen from the drawings, particularly FIG. 8, that each trailing face (31) is substantially aligned at an acute angle (49) to a tangent (51) of an inner surface (34) of the ring (17) at the point where the trailing face (31) meets the inner surface (34) of the ring (17). And similarly in FIG. 7 it can be seen that each aft face (35) is substantially aligned at an acute angle (53) to a tangent (55) of the perimeter of the container (11) at the point where the aft face (35) meets the perimeter of the container (11).

When the closure means (15) is unscrewed from the container (11), the trailing face (31) of the protrusions (25) on the ring (17) move toward the aft face (35) of the protrusions (27) on the container (11). When these faces (31) and (35) contact each other, the acute angle of the faces means that they tend not to pass over each other, but rather to become wedged together. This halts that rotation of the ring (17) and if the closure means (15) is unscrewed further the frangible link (19) will break and the ring (17) will remain about the neck (23) of the container (11).

While it is conceivable that only one container protrusion (27) is required, it is considered prudent to have two or more such protrusions (27) spaced about the perimeter of the container (11). If there are two protrusions (27) on the container (11) they should be located on opposite sides of the neck of the container (11). And where there are more than two protrusions (27) they are preferably grouped into two groups with each group being on opposite sides of the container (11). This allows a significant portion of the perimeter of the neck (23) to be clear of any protrusions as noted above.

The protrusions (27) in any group of protrusions (27) on the container (11) can be linked by a web (37) extending between adjacent protrusions (27). Preferably the or each web (37) is narrower than the protrusions (27) which it links, at least narrow in a direction perpendicular to the length of the web. It can be seen in this example that each web (37) substantially connects the upper faces (39) of adjacent protrusions (27), that is the faces (39) of each protrusion (27) that face the screw threads (13) of the container (11).

The upper faces (39) are preferably bevelled with respect to the outer surface of the container (11) to aid the passage of the ring protrusions (25) when the closure means (15) is being fitted onto the container (11). Similarly, and for the same reason, the upper face of each web (37) can be bevelled with respect to the outer surface of the container (11).

The web (37) is useful in at least two aspects. Firstly, the web (37) can prevent a ring protrusion (25) from sliding around a container protrusion (27) when the closure means (15) is being removed. This is because the joined web (37) and container protrusion (27) can provide a blind corner (41) in which the ring protrusion (25) can become trapped as the closure means (15) is being removed. And secondly, the web (37) traps one of the ring protrusions (25) and resists the migration of the ring (17) off the container (11) when the closure means (15) has been removed from the container.

FIG. 4 shows an assembled liquids packaging product (41) which incorporates a tamper evident seal (10) as described herein. In this case the container (11) is bottle shaped and the closure means (15) is also adapted for use as a drinking vessel (43).

The drinking vessel (43) comprises a body (43) (see FIG. 5) and a base (47) (see FIG. 3). The inventors have found that it is advantageous to be able to join the body (43) to the base (47) by ultrasonic welding. To do this however, the two must be made from the same material. It is advantageous to make the body (43) from a styrene plastics material due to the “glass” like qualities of styrene plastics, and the two parts can only be welded together if the base (45) is also made from the same material.

In fact, it has been this desire to manufacture the entire drinking vessel (43) from one material, and preferably from a styrene plastics material, that has lead to the need to create this new tamper evident seal design. Previous tamper evident seals require plastics with a useful degree of elasticity and memory. However styrene plastics are poor in these areas. It is for this reason that the inventor has created this seal design in which the ring portion (15) does not have to stretch, but simply has to deform slightly when being assembled onto the bottle.

As shown in FIGS. 9-23 the drinking vessel and cap have the same reference numbers for the same components as used in the drinking vessel and cap of FIGS. 1-8. However in this variation of invention, cap (15) has means (50) to allow proper twisting to break the seal (13) therebetween. This means (50) as shown in FIG. 10 has mutually opposing tabs with the words “TWIST” and “OPEN” to facilitate the breaking of the frangible seal (13) or show the direction to be taken when twisting.

As shown in FIG. 11 drinking vessel (45) is joined to cap (15) as described on page at base on page 10. Container (11) has a top end (51) and a base end (52). In other options and features in manufacturing to further facilitate the joining of the cap to the drinking vessel (45) by spin welding or any other joining method, a circumferential groove portion (53) can be provided on a top edge of the vessel (15). Also cap (15) can be provided with a downwardly and outwardly facing shelf with a protruding ridge portion or flashing (54) which is shaped to interfit within groove (53) during the joining process of welding.

Other manufacturing options as shown in FIGS. 9 and 12, the bottom of the drinking vessel (45) (which is oriented at the same point as the top of the container (11)) can be abutting or be removably attached to the outside face of the threaded portion (13) of cap (15) via a bridging portion (55). Bridging portion (55) can be joined to or formed with or abutting either the inside surface of the top portion of drinking vessel (45) and a lower position of the outer thread (13) of container (11). Portion (55) can be continuous or formed in discreet lengths circumferentially in-between the outside of the container and the inside of the vessel. This optional bridging portion (55) can be useful in providing temporary or permanent support for the joining of the drinking vessel (45) to the cap (10) either during use or during transportation or during manufacture.

Cap (15) is shown in perspective and in various side views of FIGS. 14-17 showing the directional twisting action needed to break the seal. The ring (17) is shown having pairs of ring protrusions (25) similar to that already disclosed in the other figures. As shown in the FIGS. 3, 8, 14, 15, 17 any of the faces of the ring protrusions (25) can be bevelled in the upper and lower faces and the forward and rear faces as well. Also shown in FIGS. 1, 2, 7, 19, 21) are container protrusions (27) having faces such as forward face (33), opposing aft face (35) which can be bevelled or chamfered and optionally the top and bottom faces of the container protrusions (27) can be bevelled or chamfered if necessary—see FIGS. 3 and 17. In FIGS. 19 & 21 the container protrusions (27) are joined to each other by a continuous web portion (56). FIG. 20 is similar to that shown in FIG. 7. FIG. 22 shows the base of the container (11) having protrusions (57) there-from. FIG. 23 shows the drinking vessel (45) having the groove portion (53) to allow joining to the ridge of cap (15).

Also shown in FIGS. 14, 15 & 17 are tabs (58) which are used to hold an inner cap seal to the inside of the cap to assist in pressurizing any contained fluid within the drinking vessel. These tabs (58) are shown in different sizes in this example and are useful especially during transport and movement to further enhance and retain the quality of the contained product.

VARIATIONS

Aspects of the present invention have been described by way of example Only and it should be appreciated that modifications and additions may be made thereto without departing from the scope thereof.

In the above example, the protrusions were equally spaced about the inner surface of the ring, and they were grouped in two locations about the neck of the bottle. In an alternative configuration, the protrusions could be equally spaced about the neck of the bottle, and be grouped in two locations about the inner surface of the ring. In the case where a web extended between adjacent protrusions within a group on the inner surface of the ring, the web would preferably connect the faces of adjacent protrusions that face away from the screw threads of the closure means. And preferably the face of the web facing away from the screw threads of the closure means is bevelled with respect to the inner surface of the ring.

In the above examples there are more than one protrusion on the ring (17) and on the container (11). In an alternative configuration it is envisaged that only a single protrusion could be used on the ring (17) and/or on the container (11). In a case where a single protrusion was used on both the ring (17) and on the container (11) a single start thread and careful alignment of the mating protrusions would be required.

In the above examples the container (11) is shown as a bottle shaped container, however it is envisaged that the tamper evident seal (10) could be used on a range of packaging products or containers of other shapes, for example on the lid of a jar shaped container. Similarly, while the drinking vessel (43) is shown having a ‘fluted glass’ like shape, the drinking vessel (43) could have a different shape, for example a tumbler shape.

Also, in the above examples the tamper evident seal (10) is shown as part of a closure means which is in the form of a drinking vessel, however the tamper evident seal (10) could also be part of a cap or lid or other closure device. Similarly, the closure means (15) could be a cap that is adapted to also function as a measuring device, for example, a measuring cap for use with a medicine bottle.

DEFINITIONS

Throughout this specification the word “comprise” and variations of that word, such as “comprises” and “comprising”, are not intended to exclude other additives, components, integers or steps.

ADVANTAGES

Thus it can be seen that at least the preferred form of the invention provides a tamper evident seal which can be made of a plastics material that does not have a useful degree of elasticity or memory, allowing greater manufacturing flexibility which is particularly useful in the manufacture of a drinking vessel which also acts as a closure means or cap for a drinks container. 

1. A tamper evident seal for a container having a screw thread and a closure means adapted for use with the container, the tamper evident seal comprising a normally circular ring which is frangibly linked to the closure means, the ring having one or more inwardly extending protrusions, and the container having one or more corresponding outwardly extending protrusions adjacent its screw thread, the or each protrusion on the ring having a leading face, and an opposing trailing face, and the or each protrusion on the container having a forward face and an opposing aft face, the faces being configured such that the leading face of the or each ring protrusion approaches the forward face of the or each container protrusion when the closure means is being fitted onto the container, and wherein any protrusions on the container or ring are situated or grouped in spaced apart locations about a perimeter of the container or ring and the normally circular ring is able to pass over the protrusion or protrusions on the container substantially without stretching and by deforming out of round.
 2. The tamper evident seal as claimed in claim 1 wherein the or each trailing face is substantially aligned at an acute angle to a tangent of an inner surface of the ring at the point where the trailing face meets the inner surface of the ring.
 3. The tamper evident seal as claimed in claim 2 wherein the or each aft face is substantially aligned at an acute angle to a tangent of the perimeter of the container at the point where the aft face meets the perimeter of the container.
 4. The tamper evident seal as claimed in claim 3 wherein where there are two protrusions on the container or the ring, they are located on opposite sides of the container or ring, and where there are more than two protrusions they are grouped into two groups with each group being on opposite sides of the container or ring.
 5. The tamper evident seal as claimed in claim 4 wherein each of the protrusions in any group of protrusions on the container or ring, are linked by a web extending between adjacent protrusions.
 6. The tamper evident seal as claimed in claim 5 wherein a face of the or each protrusion on the container facing the screw threads of the container is bevelled with respect to the outer surface of the container.
 7. The tamper evident seal as claimed in claim 6 wherein the or each forward face is bevelled with respect to the outer surface of the container.
 8. The tamper evident seal as claimed in claim 7 wherein the or each leading face is bevelled with respect to an inner surface of the ring.
 9. The tamper evident seal as claimed in claim 8 wherein the ring protrusions can be bevelled on their upper and/or lower faces.
 10. A liquids packaging product incorporating at least one tamper evident seal as claimed in claim
 1. 11. The liquids packaging product as claimed in claim 10 wherein the closure means is also adapted for use as a drinking vessel.
 11. The liquids packaging product as claimed in claim 11 wherein the container is substantially bottle shaped.
 12. The liquids packaging product as claimed in claim 12 wherein the closure means or drinking vessel is manufactured entirely, or primarily, from a styrene plastics material. 13-14. (canceled) 